Characterization of elastomer sliding behavior across silica and polydimethylsiloxane grafted surfaces

A novel combination of experimental techniques including a lateral force apparatus was developed for the purpose of characterizing the slip of polymer materials over hard surfaces. Quantitative shear stress data were obtained by sliding a crosslinked polydimethylsiloxane elastomer across smooth fat-tipped styli (mesas). A first set of mesas had a native silica (SiO) surface; a second set was functionalized with linear hydroxyl-terminated polydimethylsiloxane (PDMS-OH) polymers. The shear stress associated with sliding across the SiO mesas was as much as a factor of 10 greater than that for sliding across the PDMS-OR functionalized mesas. Possible mechanisms underlying this difference in behavior an discussed. (C) 2000 The Society of Rheology. [S0148-6055(00)01405-X